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US 11,378,566 B2Granted
Method for determining ammonium
AssigneeMerck Patent GmbH
InventorRalf Olt
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for determining ammonium or ammonia in aqueous samples in accordance with the known Berthelot method, wherein the risk of incorrectly low results is greatly reduced by additionally measuring the extinction in the absorption range of the nitroprusside used as a catalyst.
Claims13
A method of measuring ammonium content comprising
- a) preparing a sample having an alkaline pH and adding a chlorinating agent, a phenol derivative and nitroprusside to said sample,
- b) determining an extinction of the mixture prepared in step a) in an absorption region of blue dye formed and in an absorption region of nitroprusside,
- and wherein the extinction in the adsorption range of the resulting blue dye indicates the ammonium content and the extinction in the range of nitroprusside indicates whether or not the ammonium content measurement is plausible,
- wherein if an extinction in the absorption region of nitroprusside is above a predetermined threshold value, then the extinction of the sample in the absorption region of the blue dye formed is regarded as a plausible measurement result.
1 more element
A method of measuring ammonium content comprising
- a) adding a chlorinating agent, a phenol derivative and nitroprusside to the sample at an alkaline pH,
- b) measuring an extinction of the mixture obtained in step a) in an absorption region of blue dye formed and in an adsorption region of nitroprusside,
- wherein from the extinction in the adsorption range of the resulting blue dye indicates the ammonium content and the extinction in the range of nitroprusside indicates whether or not the ammonium content measurement is plausible,
- wherein only the presence of at least 50% of the amount of nitroprusside indicates a plausible ammonium content measurement.
1 more element
Dependencies are inferred from the claim text.